Process of degumming silk.



' small.

OTTO 3.63M,- OF DARMSTADT, GERMANY, ASSIGNOR "1E0 RGHM. 8t HAAS, OF DARMS'IAD'D',

GERMANY.

PROCESS OF DEG-UMMINGY SILK.

Patented'June e. 1916.

m 1',13 ,44@, Specification of Letters Patent.

No Drawing.

' To all whom it may concern:

this process is carried out by putrefaction These or by boiling the silk with soap. processes are objectionable. The putrefying process requires much time, and as it is a bacterial process its progress cannot well be controlled, and it develops a bad smell. The use of soap is objectionable because it attacks the silk fiber. Besides it is expensive in use, because the soap which is necessary in the process amounts on an average to 123s much as 30% of the weight of the raw sil It has been suggested to use pancreas as a degumming medium for silk. But these experiments have proved a failure as far as practical utility is concerned. My experiments to combine the use of pancreas and that of soap have had no satisfactory. re-.

Recently .I have.

to the fact, that when using enzymes of the pancreas the temperature cannot exceed 40 degrees centigrade, because the enzymes are destroyed at higher temperatures,' -while when degumming the raw silk-by means of soap the raw silk is heated to 100 degrees Centigrade. -I have found that the desired result is obtained when the silk is heated 'to 100 degrees centigrade after its treatment with the enzyme. In this case the use of soap is not absolutely necessary, but it is advisable to use alkaline salts, because-the effect is obtained thereby in a more reliable way. The amount of soap which is necessary in. the recess is exceedingly small. While hereto ore as much as from 30 to 40 per cent. of soap has been used, in my improved process one tenth of this amount is necessary. Also the amount of the enzyme which is necessary in the process is very A ancreatin solutionof part per thousand 1S suflicient. From these data it will be understood that the cost of the procscope of the the process,

. line salts at Application filed February 5, 1915. Serial No. @342.

ess is low as compared to the process which 1s based on the use of soap alone. An important advantage ofthe new process'resldes in the fact, that the silk fiber is not in the least affected by the process. I

The object in heating the silk after it has been treated in" a bath of pancreatin is tov complete the degummin and to shorten the time for doing so. TTAB sequence of the treatment of pancreatin and the heating may be reversed without departing from the invention as claime Example: The raw silk -is heated a few. hours at a temperature of not more than 40 degrees centrlgrade in an aqueous solution of pancreatin of part per thousand,

.whereupon it is heated about 20 or 30 min utes at a temperature of from 90 to 100 degrees centlgrade. If desired these steps of viz. the treatment with pancreatin solution and. the heating, carried out in the reverse order. In both cases the silk is degummed in a satisfactory way. f However, it is important, that the steps be not performed at the same time.

What I claim' and desire to secure by Letters Patent of the United States is:

1. The hereindescribed process of degumming silk and'the like', which Process comprises the step of subjecting the silk and the like tothe action of a pancreatin solution atless than 40 6.; and the step of heatmg the silkat ahigher temperature.-

2. The-hereindescribed 'rocessj of degummingsilk and the like, w ich process comprises the step of heating the silk'and the like toa temperature higher than 40 (3., and the step of subjecting the silk to the action of a pancreatin solution and salts at less thanf40- 0.;

. 3. The herein described rocess of degumming silk and the-like, w ich process comprises the step of subjecting the silk to the action of a pancreatin solution and alkaless than 40 0.; and the step of heating the silk and the like to a higher temperature.

. 4. The hereindescribed recess of degumming silk and the like,w ich process com-' prises the step of subjecting the silk to the action of-a pancreatin solution at less than the silk at a '75 may be n d v prises the step of heatin' the silk at a, temperature of 90 to l00%.; amid the step of subjecting the silk to the action of a pancreetin solution and salts at less than 40 C.

6. The herein described rocess of (legumming silk andthe like, W ieh' process comprises the step of subjecting the silk to the action of a pancreetin solution and alkaline salts at less than 40 C.; and; the step of 

